Tinplate specifications: what to ask for and why
Tinplate is thin low-carbon steel sheet coated on both sides with a very thin layer of tin. The steel gives the strength, the tin protects the steel from corroding, and a food-safe lacquer applied over it is the layer that actually touches the food. Masaş works in 0.22–0.28 mm plate across the stock range — thinner on small, shallow formats, thicker on large, deep or heavily loaded ones — and selects the interior lacquer against what the tin will hold, because a dry biscuit, an oily nut and an acidic preserve do not attack a coating in the same way. We can supply BPA non-intent lacquer, and a food-contact declaration for the coating on request. Production is certified to ISO 9001 and ISO 22000. This page sets out what each part of the specification means, what to ask for, and which documents to request — from us or from anyone else.
- Plate gauge
- 0.22–0.28 mm
- Certification
- ISO 9001 · 22000
- BPA-NI lacquer
- Available
- Food-contact declaration
- On request
The specification, line by line
| Property | What it means | At Masaş |
|---|---|---|
| Material | Low-carbon steel sheet, electrolytically coated with tin on both faces. It is not aluminium and not “tin” in the elemental sense — the tin is a coating measured in microns, and the steel underneath is what carries the load. | Food-grade tinplate throughout. Formed, printed and lacquered in our own plant in Tuzla, İstanbul. |
| Plate gauge | Thickness in millimetres. It decides rigidity, how the tin survives stacking and transit, and how much the tin weighs — and metal is the raw material cost, so gauge is a real line in the price. | 0.22–0.28 mm across the range. Small and shallow formats sit at the lower end, large trays and deep bodies at the upper end. |
| Tin coating | A very thin layer applied to both faces, quoted as a coating weight per square metre per side. Its job is corrosion protection for the steel, not food safety and not barrier performance. | Specified per project with the mill against the product and the market. Tell us what the tin will hold and we specify it rather than guessing. |
| Interior lacquer | The coating on the inside face. This — not the tin, not the steel — is the layer in contact with the food, and it is what has to be compliant. The right chemistry depends on whether the product is dry, oily, acidic or salty. | Selected against the product. BPA non-intent lacquer available. Food-contact declaration supplied on request. |
| Exterior print | Offset litho printed directly onto the sheet before forming, then finished with a protective varnish — matte, gloss or soft-touch. Printing on metal is done flat and then formed, which is why artwork has to be laid out for the forming. | Offset printed in our own hall, Pantone matched, proofed and approved before the run. Embossing and varnish options in-house. |
| Food-contact compliance | In the EU the framework is Regulation (EC) No 1935/2004 with the good manufacturing practice rules of Regulation (EC) No 2023/2006; the United States works to the relevant FDA food-contact rules. Compliance sits with the coating, and the evidence is a declaration from its manufacturer. | Declaration for the interior coating provided on request, with the quotation or before production. |
| Certification | A management-system certificate says how consistently a factory works, not what a single tin is made of. Both matter, and they answer different questions. | ISO 9001 (quality) and ISO 22000 (food safety). Working conditions audited by Intertek against the Workplace Conditions Assessment standard. |
| Barrier performance | A tin is opaque, rigid and pest-proof, which is more protection than most packaging offers. What it is not is airtight: a lid is a physical closure, not a hermetic seal. | Where a product genuinely needs an oxygen or moisture barrier, it is packed in a sealed inner bag inside the tin. We would rather tell you that than sell you the tin as something it is not. |
Choosing the interior lacquer
Coatings are not interchangeable, and the thing that decides which one you need is the chemistry of the product rather than the category it is sold in. A dry, low-fat product is undemanding: biscuits, tea, dry confectionery, pasta, most gift assortments. Fats and oils are more aggressive and can soften or leach through a coating chosen for dry goods — nuts, chocolate, halva, oily seeds. Acidic and high-salt products are the hardest case: anything with vinegar, citrus, tomato or heavy brine will attack an unsuitable coating from the inside over shelf life, and the failure shows up months after the customer has taken delivery, which is the worst time to discover it. Tell us the product, the fat and acidity if you know them, the fill weight and the intended shelf life. If you do not know them, the person who makes the product does. That is a short conversation at quotation and an expensive one afterwards.
BPA and the EU rules
Bisphenol A has been used for decades in the epoxy resins behind many food-contact coatings. Regulation (EU) 2024/3190 now prohibits BPA in the manufacture of food-contact materials in the European Union, and that prohibition explicitly covers varnishes and coatings — the category a lacquered tin falls into. It also restricts other hazardous bisphenols rather than only BPA, so a coating marketed simply as “BPA-free” is not automatically compliant with everything the regulation asks.
The regulation is being phased in by category, with the first deadlines falling during 2026 and later ones running into 2028 and 2029 for specific product types and for reusable articles. Which deadline applies to you depends on what you pack and how it is sold, and it is worth confirming with your own regulatory adviser rather than taking a supplier’s word for it — including ours. What we can tell you plainly: BPA non-intent lacquer is available from us, and we will send the declaration for the coating on your tin so your compliance file has a document in it rather than an assurance.
Documents worth asking for
- A food-contact declaration for the interior coating, from the coating manufacturer, naming the regulation it is declared against.
- Current ISO 9001 and ISO 22000 certificates — check the expiry date and the site address, not just the logo.
- A recent third-party social audit report, with its date and the site it covers.
- A pre-production sample against the approved colour proof, before the full run is printed.
- For a new shape, written confirmation of who owns the tooling and where it is stored.
None of these are unusual requests, and a manufacturer should be able to produce all five without a delay. Ask every supplier for the same set, us included, and compare what actually arrives.
Technical questions buyers ask
What thickness of tinplate is used for tin boxes?
Across our stock range, 0.22–0.28 mm. Which end of that band a given tin sits at is decided by its size and how it will be loaded rather than by preference: a small shallow tin is rigid enough at the lower end, while a large tray or a deep body needs the upper end to survive stacking and transit without deforming. Specifying thinner than the format needs is a false economy that shows up as damage on arrival.
Is tinplate food-safe?
The part that touches the food is the interior lacquer, not the tin or the steel, so the honest answer is that a correctly specified and correctly lacquered tin is food-safe and the evidence for it is the coating’s food-contact declaration. In the EU the framework is Regulation (EC) No 1935/2004 together with the good manufacturing practice rules of Regulation (EC) No 2023/2006. Ask for the declaration rather than for reassurance — we send it on request.
Are your tins BPA-free?
We can supply BPA non-intent lacquer, and the declaration for the coating used on your order. It is worth being precise about the wording: Regulation (EU) 2024/3190 restricts other hazardous bisphenols as well as BPA itself, so “BPA-free” on its own does not answer every question the regulation asks. The document does. Tell us the market you are selling into and we will make sure the coating on your tin is specified for it.
Does a tin keep coffee or spices fresh?
It protects them from light, crushing, pests and pilferage far better than board or film, and an inner plug lid holds a reseal better than any other closure we make. But a metal lid is not a hermetic seal, so for whole beans, ground coffee or ground spices with a long shelf life the barrier is a sealed inner bag — with a degassing valve for coffee — and the tin is the reusable outer pack around it. Anyone who tells you the tin alone is an oxygen barrier is overselling it.